Geokge w



(No Model.;

G. W. LUTZ.

GOMPRBSSIBLE-PISTON. No; 262,962. Patented Aug'. 22, 1882.

J5 L waz faz:

n. PETERS. Mmmm-wmf. wahingm. D. a

UNITED STATES PATENT OFFICE.

GEORGE W. LU'IZ, OF INDIANAPOLIS, INDIANA.

COMPRESSIBLE P'ISTON.

SPECIFICATION forming part of Letters Patent No. 262,962, dated August 22, 1882.

Application led J une 5, 1882.

l `To allvwhom it may concern.;

Be it known that I, GEORGE W. LUTZ, Vof Indianapolis, Indiana, have invented a new and useful Improvement in Compressible Pistons, of which the following is a description, referencebein g had to theaccompanyin g drawings, like letters in the figures indicating like parts.

My invention relates to that class ot' pistons which are made of leatheror soft material, which is likely to harden and become loose in the cylinder when dry; and my object is to provide means for enlarging the piston by compression from without the cylinder to tighten it instantly when required.

My device is capable of adaptation to many machines; but l have illustrated itin the drawings as connected with a Ihypodermic syringe, where it is of great value. The simplicity ot' its construction is such that it can readily be adj usted by any ordinary person. y

In the drawings, Figure l represents an ordinary hypodermic syringe having an opening in its metal shell disclosing the glass cylinder within and my piston` in the cylinder. Fig. 2 represents a longitudinal section of the same.

A is the outeror metal shell of a syringe.

C is a piston-rod working in an outer case, B, to the inner end of which is attached a nut, l). The inner rod, o, is threadedto fit the nut D.`

E is a core ot rubber, and a a a" are a series of leather rings ornvashers tting over the central rubber core, E. The piston-rod O passes through the nut D, next to which is a (No model.)

inner rod firmly by the handle and turning the outer case, B, from you, or to the right, the nut D tightens down upon the leather rings and the rubber core., and the latter, being thus compressed, enlarges its diameter and forces the 'leather rings outward until the cylinder is completely fitted and the piston becomes tight. The reverse process relieves the rubber core and rings of the compression, and the piston works more freely in the cylinder.

I am aware that compressible pistons have been used in some cases before, and I do not broadly claim such a one; but I believe that my device for compressing a central rubber core surrounded by leather rings from outside the cylinder and at any point along the barrel, in the manner indicated, is new.

What I claim, and desire to secure by Letters Patent, is-

1. Apiston ccmposedof' a central elastic core surrounded by washersV of compressible material connected with a piston-rod composed of an outer shell or case, through which an inner rod passes the entire length, passing also through the piston, andV threaded to work in a nut'attached to the inner end of the outer shell for compressing the piston, Substantially as speciiied.

2. The combination, in a piston, of a central elastic core with outer compressible rings litting around the core, and apiston-rod composed of an inner stem passing through the core and an outer shell, the tw""o connected by a screw and nut for expandingv the piston by compression at any point along the barrel, substantially as described.

3. The combination of an outer cylinder with a piston composed of the elastic core E, outer rings, orY a' a, and piston-rod O, with the outer case, B, and nut D, substantially as and for thepurpose specified.

In witness whereotl I have hereunto set my hand this 1st day of June, 1882.

GEORGE W. LUTZ.

Witnesses:

0.3?. JAcoBs, JACOB W. LoEssER. 

